Cryogenic low noise MMIC amplifiers for U-Band (40–60 GHz)

In this work, we describe monolithic millimeter-wave integrated circuit (MMIC) Low Noise Amplifier (LNA) and mixer designs for U-Band, also known as the WR19 waveguide band (40–60 GHz). The LNAs were fabricated in NGC's 35 nm InP HEMT MMIC process. The MMICs were packaged in WR19 waveguide housings and tested for noise, both at room temperature and cryogenically. We present the results, including a comparison to the state-of-the-art, and discuss applications for amplifiers in this frequency range. To date, these are the first cryogenic 35 nm InP MMIC results covering the 40–60 GHz range. We achieved a noise temperature less than 30 K over the 40–60 GHz range, when the amplifiers were cryogenically cooled. These results are comparable with other results in the literature, and we believe are the lowest reported for MMICs in the 50–60 GHz range.